Light source apparatuses that have light sources and that output light have been used, for example for image display apparatuses, such as projectors that modulate light based on an image signal and project an image represented by the image signal. In such light source apparatuses, the higher the temperature of the light source, the more likely will the luminous efficiency become lower and/or the light sources will not work. Thus, a variety of cooling techniques using cooling means that cool the light sources such as a fan and a Peltier element have been studied.
Patent Document 1 (JP2005-121890A) discloses a technique that controls driving of cooling means for an image display apparatus having a light source apparatus based on an input image signal. According to the technique disclosed in Patent Document 1, if an image signal that represents a dark image is input to the image display apparatus, the temperature of the light source is kept constant and the current consumption is decreased in such a manner that the output of the light source is decreased, the number of revolutions of the fan is decreased, and the amount of current supplied to the Peltier element is decreased.
Patent Document 2 (WO2009/008166 A1) discloses a technique that provides a temperature sensor in the neighborhood of a light source of a light source apparatus and drives cooling means in such a manner that the temperature of the light source is kept constant based on the temperature measured by the temperature sensor.